1. Field of the Invention
The present invention relates to methods for dyeing a material, comprising treating the material with a dyeing system which comprises one or more reduced vat dyes and/or one or more reduced sulfur dyes, and oxidizing the one or more reduced vat dyes and/or one or more reduced sulfur dyes adsorbed onto the treated material with an oxidation system comprising (a) an oxygen source and one or more enzymes exhibiting oxidase activity or (b) a hydrogen peroxide source and one or more enzymes exhibiting peroxidase activity; wherein the material is a fabric, yarn, fiber, garment or film made of cotton, diacetate, flax, fur, hide, leather, linen, lyocel, polyacrylic, polyamide, polyester, ramie, rayon, silk, tencel, triacetate, viscose or wool. The present invention also relates to materials dyed by such methods.
2. Description of the Related Art
Dyeing of textiles is often the most important and expensive single step in the manufacturing of textile fabrics and garments. In the textile industry, two major types of processes are currently used for dyeing, i.e., batch and continuous. In the batch process, among others, jets, drums, and vat dyers are used. In continuous processes, among others, padding systems are used. See, e.g., I. D. Rattee, In C. M. Carr (editor), The Chemistry of the Textiles Industry, Blackie Academic and Professional, Glasgow, 1995, p. 276.
There are two types of dyes involving a reduction/oxidation mechanism, i.e., vat and sulfur dyes. The purpose of the reduction step in these dyeings is to change the dyestuff from an insoluble form to a soluble form. The oxidation step then converts the soluble dye back to the insoluble dye thereby fixing the dye to the dyed material.
Oxidoreductases, e.g., oxidases and peroxidases, are well known in the art.
One class of oxidoreductases is laccases (benzenediol:oxygen oxidoreductases) which are multi-copper containing enzymes that catalyze the oxidation of phenols and related compounds. Laccase-mediated oxidation results in the production of aromatic radical intermediates from suitable substrates; the ultimate coupling of the intermediates so produced provides a combination of dimeric, oligomeric, and polymeric reaction products. Such reactions are important in nature in biosynthetic pathways which lead to the formation of melanin, alkaloids, toxins, lignins, and humic acids.
Another class of oxidoreductases are peroxidases which oxidize compounds in the presence of hydrogen peroxide.
Laccases have been found to be useful for hair dyeing. See, e.g., PCT applications Serial No. PCT/US95/06815 and PCT/US95/06816. European Patent No. 0504005 discloses that laccases can be used for dyeing wool at a pH in the range of between 6.5 and 8.0.
U.S. Pat. No. 5,538,517 disclosed methods for dyeing keratin fibers with indole or indoline derivatives which after oxidation with hydrogen peroxide in the presence of a peroxidase produces strong colorations.
Saunders et al., Peroxidase, London, 1964, p. 10 ff. disclose that peroxidases act on various amino and phenolic compounds resulting in the production of a color.
Japanese Patent Application publication no. 6-316874 discloses a method for dyeing cotton comprising treating the cotton with an oxygen-containing medium, wherein an oxidoreductase selected from the group consisting of ascorbate oxidase, bilirubin oxidase, catalase, laccase, peroxidase, and polyphenol oxidase is used to generate the oxygen.
Japanese Patent Application publication no. 2-104773 discloses a method for indigoid dyeing of a material using an enzyme selected from the group consisting of napthalene dioxygenase, toluene oxygenase, benzene dioxygenase, indole hydrolase, and xylene oxidase.
WO 91/05839 discloses that oxidases and peroxidases are useful for inhibiting the transfer of textile dyes.
Japanese Patent Application publication no. 08-127976 discloses a method for dyeing a keratin-coated fiber by immobilizing a peroxidase to the fiber, immersing the peroxidase-immobilized fiber in an aqueous solution containing a reduced dye, and enzymatically oxidizing the reduced dye in the presence of hydrogen peroxide with the immobilized peroxidase.
It is an object of the present invention to provide new enzymatic methods for dyeing materials with reduced vat and/or sulfur dyes.